To address the problems that power customers lac k motivation for carbon reduction and that the extensive existing energy consumption patterns prevent the full exploitation of carbon reduction potential on the user side and result in low energy utilization efficiency，an economic optimization method for integrated energy systems is proposed by incorporating a carbon trading mechanism.First，a stepped positive-negative carbon trading mechanism is introduced to guide users to reduce carbon emissions through financial profit and loss.A two-stage optimization is then applied to the power-to-gas device，and combined heat and power with an adjustable heat-to-power ratio is adopted to develop an integrated energy system model based on electricity-hydrogen interaction，thereby improving the energy utilization efficiency of the integrated energy system.Finally，by considering a demand response based on electricity price，a low-carbon demand response optimization method for an integrated energy system based on an improved carbon trading mechanism is proposed to further reduce carbon emissions and economic costs.The comparison results of multiple experimental scenarios show that the proposed method reduces the carbon emissions of the system by 3.97% compared to the stepped carbon trading mechanism，with an additional 1.58% reduction in carbon emissions and a 0.11% reduction in economic costs when combined with demand response.